How Can Ozone and Relative Humidity Affect Artists’ Alkyd Paints? A FT-IR and Py-GC/MS Systematic Study

Knowledge of the chemical–physical reactions that determine the main degradation behaviour of artists’ alkyd paints represents one of the main problems within the museum exhibitions. The collection and interpretation of these data on degradation phenomena, especially after ozone exposure at different relative humidity values, can be useful for their conservation needs. Therefore, a systematic investigation of these materials may help achieve this goal. Firstly, surface-level identification of the main functional groups of ad hoc created and aged alkyd paints was performed using attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR). Subsequently, these paints were investigated by pyrolysis–gas chromatography and mass spectrometry (Py–GC/MS), allowing for precise bulk identification of the organic compounds before and after accelerated ageing. A first successful attempt to provide quantitative Py–GC/MS data on alkyd-based paints is here presented and discussed. Comparing the results, it was possible to obtain new insights into the degradation behaviour of alkyd paints when exposed to ozone, allowing us to devise specific preventive and conservation strategies for these artistic materials

Data Fusion Approach to Simultaneously Evaluate the Degradation Process Caused by Ozone and Humidity on Modern Paint Materials

The knowledge of the atmospheric degradation reactions affecting the stability of modern materials is still of current interest. In fact, environmental parameters, such as relative humidity (RH), temperature, and pollutant agents, often fluctuate due to natural or anthropogenic climatic changes. This study focuses on evaluating analytical and statistical strategies to investigate the degradation processes of acrylic and styrene-acrylic paints after exposure to ozone (O3) and RH. A first comparison of FTIR and Py-GC/MS results allowed to obtain qualitative information on the degradation products and the influence of the pigments on the paints’ stability. The combination of these results represents a significant potential for the use of data fusion methods. Specifically, the datasets obtained by FTIR and Py-GC/MS were combined using a low-level data fusion approach and subsequently processed by principal component analysis (PCA). It allowed to evaluate the different chemical impact of the variables for the characterization of unaged and aged samples, understanding which paint is more prone to ozone degradation, and which aging variables most compromise their stability. The advantage of this method consists in simultaneously evaluating all the FTIR and Py-GC/MS variables and describing common degradation patterns. From these combined results, specific information was obtained for further suitable conservation practices for modern and contemporary painted films

Quanti-qualitative evaluation of pectins in the dietary fibre of 24 foods

The dietary fibre of 24 foods was analysed for its proportions of insoluble and soluble (SDF) fractions and for its contentof high methoxyl pectins (HM), low methoxyl pectins (LM) and protopectin. The fractional extraction and quantitativedetermination of pectins were performed on the total dietary fibre residue, following the procedure suggested byRobertson (1979). Total pectin content (TP), calculated as sum of the three fractions, ranged from 2.4 to 49.8 g/kg ofdry matter. The variation coefficient of TP measurements repeated on the same foods were, on average, 2%. Total pectincontent was 49.8 g/kg DM in dried beet pulp and averaged 33.8+_0.3 g/kg DM in fruits and vegetables, 13.2+_8.4 g/kgDM in legumes and tubers and only 2.8+_0.5 g/kg DM in cereals. HM fraction prevailed in apple and pear samples (>40%of TP), while LM and protopectin largely prevailed in legumes and vegetables. A strong variability among foods was foundfor the TP/SDF ratio. In general, within each food category, increasing levels of SDF were associated with decreasing valuesof TP/SDF ratio. Since many foods contain low amounts of pectins, care in the development of calibration curves forspectrophotometric reading is required. Finally, the whole procedure for pectin extraction and quantification on dietaryfibre of food is very complex and time-consuming

Linking inflammation and hypertension in humans: studies in Bartter's/Gitelman's syndrome patients

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Intra-articular etanercept treatment for severe diffuse pigmented villonodular knee synovitis

Pigmented villonodular synovitis (PVNS) is a rare pre-malignant disease that require aggressive treatment as surgical synovectomy, eventually followed by radiosynovectomy. Nevertheless, the disease often reoccurs after these treatments. To determine the safety and efficacy of intra-articular (IA) TNF-a blockade with etanercept (ETN), before extended arthroscopic synovectomy, in severe PVNS of the knee, two patients, (a 26-year-old man with B27+ undifferentiated spondylarthropathy and a 32-year-old femal with seronegative olygoarthritis), affected by diffuse knee PVNS (diagnosis made by histological examination), resistant to IA corticosteroid injections and to repeated arthroscopic synovectomy, were submitted, after protocol approval by human research committee and patient's written informed consent to intra-articular etanercept (IA-ETN) treatment with a different dosage schedule: 12.5 mg weekly IA-ETN injection for 4 weeks, followed by extended arthroscopic synovectomy and of 25 mg IA-ETN injection for 4 weeks, respectively. Previous DMARDs treatment was continued in stable appropriate doses. Any adverse events were recorded throughout the study. The following parameters were considered as clinical endpoints: 1) Knee Joint Index (KJI: range 0-14); 2) Thompson index (THI: range 0-9) At the study entry and at the end of follow-up, high frequency ultrasound grey scale synovial thickening (US-ST) was also assessed. No adverse events were observed due to IA-ETN and to arthroscopic synovectomy. Marked improvement of knee disease activity over time and sustained functional recover was obtained. US-ST evaluation before treatment initiation and at the end of follow-up confirmed the regression of knee joint synovial proliferatio

The Redox Enzyme p66Shc Contributes to Diabetes and Ischemia-Induced Delay in Cutaneous Wound Healing

OBJECTIVE: The redox enzyme p66Shc produces hydrogen peroxide and triggers proapoptotic signals. Genetic deletion of p66Shc prolongs life span and protects against oxidative stress. In the present study, we evaluated the role of p66Shc in an animal model of diabetic wound healing. RESEARCH DESIGN AND METHODS: Skin wounds were created in wild-type (WT) and p66Shc(-/-) control and streptozotocin-induced diabetic mice with or without hind limb ischemia. Wounds were assessed for collagen content, thickness and vascularity of granulation tissue, apoptosis, reepithelialization, and expression of c-myc and beta-catenin. Response to hind limb ischemia was also evaluated. RESULTS: Diabetes delayed wound healing in WT mice with reduced granulation tissue thickness and vascularity, increased apoptosis, epithelial expression of c-myc, and nuclear localization of beta-catenin. These nonhealing features were worsened by hind limb ischemia. Diabetes induced p66Shc expression and activation; wound healing was significantly faster in p66Shc(-/-) than in WT diabetic mice, with or without hind limb ischemia, at 1 and 3 months of diabetes duration and in both SV129 and C57BL/6 genetic backgrounds. Deletion of p66Shc reversed nonhealing features, with increased collagen content and granulation tissue thickness, and reduced apoptosis and expression of c-myc and beta-catenin. p66Shc deletion improved response to hind limb ischemia in diabetic mice in terms of tissue damage, capillary density, and perfusion. Migration of p66Shc(-/-) dermal fibroblasts in vitro was significantly faster than WT fibroblasts under both high glucose and hypoxia. CONCLUSIONS: p66Shc is involved in the delayed wound-healing process in the setting of diabetes and ischemia. Thus, p66Shc may represent a potential therapeutic target against this disabling diabetes complication

Efficient Verifiable Computation of XOR for Biometric Authentication

This work addresses the security and privacy issues in remotebiometric authentication by proposing an efficient mechanism to verifythe correctness of the outsourced computation in such protocols.In particular, we propose an efficient verifiable computation of XORingencrypted messages using an XOR linear message authenticationcode (MAC) and we employ the proposed scheme to build a biometricauthentication protocol. The proposed authentication protocol is bothsecure and privacy-preserving against malicious (as opposed to honest-but-curious) adversaries. Specifically, the use of the verifiable computation scheme together with an homomorphic encryption protects the privacy of biometric templates against malicious adversaries. Furthermore, in order to achieve unlinkability of authentication attempts, while keeping a low communication overhead, we show how to apply Oblivious RAM and biohashing to our protocol. We also provide a proof of security for the proposed solution. Our simulation results show that the proposed authentication protocol is efficient

Measuring stress in medical education: validation of the Korean version of the higher education stress inventory with medical students

Background: Medical students face a variety of stressors associated with their education; if not promptly identified and adequately dealt with, it may bring about several negative consequences in terms of mental health and academic performance. This study examined psychometric properties of the Korean version of the Higher Education Stress Inventory (K-HESI). Methods: The reliability and validity of the K-HESI were examined in a large scale multi-site survey involving 7110 medical students. The K-HESI, Beck Depression Inventory (BDI) and questions regarding quality of life (QOL) and self-rated physical health (SPH) were administered. Results: Exploratory factor analysis of the K-HESI identified seven factors: Low commitment; financial concerns; teacher-student relationship; worries about future profession; non-supportive climate; workload; and dissatisfaction with education. A subsequent confirmatory factor analysis supported the 7-factor model. Internal consistency of the K-HESI was satisfactory (Cronbach's a = .78). Convergent validity was demonstrated by its positive association with the BDI. Known group validity was supported by the K-HESI's ability to detect significant differences on the overall and subscale scores of K-HESI according to different levels of QOL and SPH. Conclusions: The K-HESI is a psychometrically valid tool that comprehensively assesses various relevant stressors related to medical education. Evidence-based stress management in medical education empirically guided by the regular assessment of stress using reliable and valid measure is warranted.open